Smith played for the first time since suffering a serious knee injury in the Fiesta Bowl after the 2015 season, his junior year at Notre Dame. He started Saturday at middle linebacker for the Cowboys and was credited with one tackle.

Sean Lee was out with a hamstring strain, so Anthony Hitchens moved to weakside linebacker, allowing Smith to start at middle linebacker. Smith did not come off the field when the Cowboys went to their nickel defense. He stopped Colts tight end Jack Doyle short of a first down on the second series. He overran a couple of plays on the third series, but he was active.

He is hoping the narrative moves from his comeback to his play on the field.

"Do my job," he said. "Have a sense of urgency of getting lined up, going over my keys, and playing football."

Jaylon Smith was active in his first game action since the 2015 college football season. Tim Heitman/USA TODAY Sports

QB depth chart:Dak Prescott had his best practice of training camp on Wednesday when he completed all 18 of his passes in team and 7-on-7 drills. He was just as efficient in his opening action of the preseason Saturday. He finished two series, completing 7 of 8 passes for 106 yards and a touchdown pass of 32 yards to WR Dez Bryant. Prescott's only incompletion came on a batted-down pass at the line of scrimmage. He left after 17 plays.

When it was starters vs. starters, the Cowboys looked...: Would outstanding be too strong? Yes, RB Darren McFadden fumbled on the second drive, but the Cowboys faced third down just once on the first two drives and WR Cole Beasley converted that. McFadden ran for 59 yards on nine carries. TE Jason Witten had two first-down catches. The defense had two three-and-outs and did not allow a first down in the first quarter. That has to give the Cowboys confidence going into their next preseason game against the Oakland Raiders, when the starters could play into the third quarter.

One reason to be concerned: QB Kellen Moore did himself no favors with a sack-fumble that was returned by former Cowboy Lavar Edwards for a Colts touchdown. That came after an ineffective 8-of-17, 69-yard showing against the Los Angeles Rams in the first preseason game. In six series, Moore completed 10 of 21 passes for 131 yards and directed the Cowboys to one scoring drive. Meanwhile, rookie QB Cooper Rush needed just six plays to deliver a touchdown pass on his first series.

That guy could start:Jonathan Cooper started at left guard, but his work at center in the second quarter needs to draw some attention. While he may end up winning the left guard competition over Chaz Green and Byron Bell, Cooper's ability to play center could allow the Cowboys position flexibility when composing their 53-man roster. In the third quarter, Cooper moved back to left guard.

Rookie watch: It is always a good sign for a rookie when he is included on the first-team special-teams units. Wide receiver Noah Brown, a sixth-round pick, worked on the first kickoff return and punt coverage teams. His third-quarter unnecessary roughness penalty on a punt return won't make the coaches happy, but a 19-yard touchdown catch in the third quarter will. He should be penciled in on the final roster.

Ho-hum: Bryant spoke Thursday at how excited he was to play in the preseason. No, seriously. He caught Prescott's first pass and ended the first drive with a 32-yard touchdown on a stutter-go, back-shoulder throw; Bryant was able to spin away from Colts cornerback Vontae Davis and take a hit from safety Darius Butler before getting to the end zone.

In their last 10 games, counting preseason and playoffs, Prescott and Bryant have connected for nine touchdowns. Just something to keep in mind.

Get after the run: DE Benson Mayowa led the Cowboys in sacks last year with six, but his work Saturday against the run drew attention. He had a first-quarter tackle and a tackle for loss in the second quarter. A knee issue kept him out of the first two preseason games, but he started Saturday and was noticeable. The Cowboys need him to get after the quarterback more, but he helped keep the Colts without a first down in the first quarter.

Take a licking: Running backs coach Gary Brown last played in the NFL in 1999, so it's been a while since he took a hit. Brown was rolled on the sideline by Colts receiver Kamar Aiken, who was shoved by Dallas safety Jeff Heath. Brown was slow to get up. He was examined by the Cowboys' medical staff and soon was joking with his runners, including McFadden and Ezekiel Elliott.